1. Field of the Invention
The present invention relates to an image sensor module suitable for use in a handy-type image input apparatus which is held by hand and slid across a document to read out an image of the document.
2. Description of the Related Art
Typically, the image sensor module comprises an image sensor device having a plurality of sensor elements, and a printed circuit board on which the image sensor device and control circuits for the image sensor device are mounted. The sensor elements are arranged in a straight line, and connections between the sensor elements and the control circuits are arranged on both sides of that line, as disclosed, for example, in Japanese Unexamined Patent Publication (Kokai) No. 62-126665.
An image of a document is read out by touching the image sensor to a surface of a document and by sliding the image sensor in a direction perpendicular to the line of sensor elements. Therefore, the image sensor must be placed at an exact position on the document in order to exactly read out a required portion of the document. Nevertheless, it is not easy to exactly place the image sensor at the required position on the document, because there is a certain distance between an edge portion and a sensing portion in the image sensor module because of the existence of the aforementioned connections between the sensor elements and the control circuits.
Additionally, as the distance between the edge portion and the sensing portion is large, it is difficult to read out the center portion of a spread open bulky book or magazine.
Furthermore, the conventional image sensor module has a certain width due to the connections arranged on both sides of the sensor elements, so that exact imaging cannot be performed if the document has an uneven surface or it is bent, because the image sensor cannot be kept in contact with the surface of the document